JP6996884B2 - Image processing equipment, image processing methods and programs - Google Patents

Description

Embodiments of the present invention relate to image processing devices, image processing methods and programs.

An image forming apparatus such as an MFP (multifunction peripheral) converts data described in a page description language (PDL (page description language)) such as PostScript or PDF (Portable Document Format) into raster data for printing. image processor) Processing may be performed. The RIP process can be divided into an analysis process and a drawing process. The analysis process includes a process of dividing a plurality of pages of data into intermediate data of a plurality of single pages. The drawing process includes a process of converting the intermediate data processed by the analysis process into raster data for printing. The raster data for printing is hereinafter referred to as "printing data".
The image forming apparatus may store the data converted by the RIP process in a storage device such as a memory or an HDD (hard disk drive). However, when the data to be printed is a high-resolution color image, it may be too large to be stored in the storage device included in the MFP. For this reason, the image is compressed and then stored. Since the compression process takes time if it is performed by software, dedicated hardware called a compression core or the like may be used.
Further, as the image forming apparatus, a processor having a plurality of cores such as a multi-core CPU (central processing unit) or a CPU having a built-in GPU (graphics processing unit) may be adopted. Then, the processor operates as a RIP, and the analysis process and the drawing process are processed in parallel by a multi-thread or the like to improve the speed of the RIP process. However, even if the processing speed of RIP by the processor is improved in this way, the speed of compression processing by the compression core may become a bottleneck. That is, even if the drawing processing is advanced one after another by parallel processing or the like, if the compression core is not free, a processing wait occurs before the compression processing is started for the data for which the RIP processing has been completed. In this case, the speed of the entire processing including the RIP processing and the compression processing hardly changes only by increasing the usage rate of the processor. Further, since the processor included in the image forming apparatus performs various processes other than the RIP process, if the usage rate is excessively increased by the RIP process, other processes may become heavy.

Japanese Unexamined Patent Publication No. 2004-38527

An object to be solved by an embodiment of the present invention is to provide an image processing device, an image processing method, and a program that can efficiently use a processor.

The image processing apparatus of the embodiment has an analysis unit that performs an analysis process that converts print target data into intermediate data divided into a plurality of print units, and an intermediate data divided into a plurality of print units into print data, respectively. It is provided with a plurality of drawing processing units that perform drawing processing in parallel, and a compression unit that compresses the print data converted by the drawing processing . Each time the first intermediate data is converted from the print target data, the analysis unit converts the number of idle compression units plus an arbitrary set value larger than zero into the print data. Compare whether it is larger than the number of second intermediate data in. When the added number is larger than the number of the second intermediate data, the analysis unit instructs the drawing processing unit that has not executed the drawing process to start the drawing process of the first intermediate data. When the added number is not larger than the number of the second intermediate data, the analysis unit adds the first intermediate data to the drawing waiting queue, and the added number is the number of the second intermediate data. When it becomes larger than, the drawing processing unit that has not executed the drawing process is instructed to start the drawing process of the first intermediate data added to the drawing waiting queue.

The block diagram which shows the main part circuit composition of the image forming apparatus which concerns on embodiment. The flowchart which shows the control process by a processor in FIG. The flowchart which shows the control process by a processor in FIG. The flowchart which shows the processing by the compression core in FIG. The figure which shows an example of the processing timing of the conventional RIP processing and compression processing. The figure which shows an example of the processing timing of RIP processing and compression processing. The figure which shows an example of the processing timing of RIP processing and compression processing of an embodiment. The figure which shows an example of the processing timing of RIP processing and compression processing of an embodiment.

Hereinafter, the image forming apparatus according to the embodiment will be described with reference to the drawings.
FIG. 1 is a block diagram showing a main circuit configuration of the image forming apparatus 10 according to the embodiment. The image forming apparatus 10 is an MFP or a copier having functions such as printing, scanning, copying and facsimile. Alternatively, the image forming apparatus 10 is a printer or the like having a printing function. The image forming apparatus 10 includes a processor 11, a ROM (read-only memory) 12, a RAM (random-access memory) 13, an auxiliary storage device 14, a compression core 15, an image forming unit 16, and a bus 17. The image forming apparatus 10 is an example of an image processing apparatus.

The processor 11 corresponds to a central part of a computer that performs processing such as calculation and control necessary for the operation of the image forming apparatus 10. The processor 11 controls each part to realize various functions of the image forming apparatus 10 based on a program such as system software, application software, or firmware stored in the ROM 12 or the auxiliary storage device 14. The processor 11 is, for example, a CPU (central processing unit), an MPU (micro processing unit), a SoC (system on a chip), a DSP (digital signal processor), a GPU (graphics processing unit), or the like. Alternatively, the processor 11 is a combination of these. The processor 11 is preferably a multi-core CPU or a processor including a GPU and a CPU. This is because a processor having a plurality of cores can perform high-speed processing by performing parallel processing such as multithreading or multiprocessing. In addition, the parallel processing is to process a plurality of threads or processes simultaneously while switching by time division or the like, or to perform parallel processing. Further, parallel processing means processing a plurality of threads or processes at the same time by a plurality of cores.

The ROM 12 corresponds to the main storage device of a computer centered on the processor 11. The ROM 12 is a non-volatile memory used exclusively for reading data. The ROM 12 stores the above program. Further, the ROM 12 stores data or various set values used by the processor 11 for performing various processes.

The RAM 13 corresponds to the main storage device of a computer centered on the processor 11. The RAM 13 is a memory used for reading and writing data. The RAM 13 is used as a so-called work area or the like for storing data temporarily used by the processor 11 for performing various processes.

Further, the RAM 13 and the like store the variable p, the variable q, and the variable r. The variable p indicates how many threads the processor 11 is executing the drawing process. The initial value of the variable p is 0. The number of threads in which the processor 11 is executing the drawing process is hereinafter referred to as "the number of drawing threads". The variable q indicates the number of compressed cores 15 in the idle state. The initial value of the variable q is the number of compression cores 15. The number of compressed cores 15 in the idle state is hereinafter referred to as "the number of free cores". The variable r indicates the number of queues waiting for compression (hereinafter referred to as “number of waits for compression”). The initial value of the variable r is 0. The compression waiting queue is a list of print data waiting for compression processing. Therefore, the number of waits for compression indicates the number of print data waiting for the compression process.

Further, the RAM 13 and the like store compression core information indicating whether each compression core 15 is in an idle state or a busy state. The idle compression core 15 is vacant because the compression process is not performed. The busy compression core 15 is not vacant because the compression process is performed. The compressed core information is stored in association with a core ID (identifier), which is a unique identification number assigned to each of the compressed cores 15, and a parameter indicating whether the compressed core is in an idle state or a busy state.

The auxiliary storage device 14 corresponds to an auxiliary storage device of a computer centered on the processor 11. The auxiliary storage device 14 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), an SSD (solid state drive), or the like. The auxiliary storage device 14 may store the above program. Further, the auxiliary storage device 14 stores data used by the processor 11 for performing various processes, data generated by the processes of the processor 11, various setting values, and the like. The image forming apparatus 10 may include an interface capable of inserting a storage medium such as a memory card or a USB (Universal Serial Bus) memory in place of the auxiliary storage device 14 or in addition to the auxiliary storage device 14. ..
The auxiliary storage device 14 also stores the set value k. The set value k is an arbitrary value set by, for example, a designer, an administrator, a serviceman, or the like of the image forming apparatus 10. The value of the set value k is set according to, for example, the time required for the analysis process, the time required for the drawing process, the time required for the compression process, the number of compressed cores, the number of cores of the processor 11, and the like. The value of the set value k is preferably a number larger than 0. This is because when the set value k is 0, the compression core 15 is often vacant, and the overall processing speed may be slowed down. This can be reduced by making the set value larger than 0. The value of the set value k is more preferably 1. This is because if the set value k is set too large, the usage rate of the processor 11 will only increase and the overall processing speed will hardly change. The set value k will be further described later. The set value k is an example of a predetermined number.

The program stored in the ROM 12 or the auxiliary storage device 14 includes a control program described for the control process described later. As an example, the image forming apparatus 10 is transferred to the manager of the image forming apparatus 10 or the like in a state where the control program is stored in the ROM 12 or the auxiliary storage device 14. However, the image forming apparatus 10 may be transferred to the administrator or the like in a state where the control program described for the control process described later is not stored in the ROM 12 or the auxiliary storage device 14. Further, the image forming apparatus 10 may be transferred to the administrator or the like in a state where another control program is stored in the ROM 12 or the auxiliary storage device 14. Then, the control program described for the control process described later may be separately transferred to the administrator or the like and written to the ROM 12 or the auxiliary storage device 14 under the operation of the administrator or the serviceman. The transfer of the control program at this time can be realized by recording on a removable storage medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory, or by downloading via a network.
The above control program includes a RIP program for the processor 11 to perform RIP processing.

The ROM 12 or the auxiliary storage device 14 stores a job list which is a list of unprinted print jobs. The print job includes data such as an image or a document to be printed (hereinafter referred to as "print target data").

The processor 11 operates as the RIP 111 by executing the RIP program.
RIP111 performs RIP processing for converting the data described in PDL into print data. The RIP 111 includes an analysis unit 112 and a drawing processing unit 113.

The analysis unit 112 performs an analysis process including a process of decomposing the print target data of a plurality of pages described in PDL into data for each page. The print target data is converted into intermediate data by performing analysis processing by the analysis unit 112. The intermediate data is data that can perform the drawing process shown below. The analysis process is a sequential process. This is because the data described in PDL does not always match the description order of the elements and the appearance order, and there are also elements that span multiple pages, making it difficult to process in parallel. be. One page is an example of one print unit.
The drawing processing unit 113 performs drawing processing for converting intermediate data into printing data. The print data includes information indicating what color is to be printed for each print pixel. The intermediate data converted by one drawing processing unit 113 in one drawing process is an example of print target data for one print unit.

The compression core 15 is, for example, a hardware accelerator that compresses print data for which RIP processing has been completed. Although two compression cores 15 are shown in FIG. 1, the number of compression cores 15 is not limited to two. That is, the number of the compression cores 15 may be one or three or more. Each compression core 15 stores a core ID assigned to itself. The compression core 15 is an example of a compression unit.

The image forming unit 16 prints by forming an image or the like with ink or the like on a sheet-shaped recording medium such as paper. The image forming unit 16 prints based on printing data and the like. The image forming unit 16 includes, for example, a laser printer, an inkjet printer, or another printer.

The bus 17 includes a control bus, an address bus, a data bus, and the like, and transmits signals transmitted and received by each part of the image forming apparatus 10.

Hereinafter, the operation of the image forming apparatus 10 according to the embodiment will be described with reference to FIGS. 2 to 8. The content of the process in the following operation description is an example, and various processes that can obtain the same result can be appropriately used. 2 and 3 are flowcharts of control processing by the processor 11 of the image forming apparatus 10. The processor 11 executes this control process based on the control program stored in the ROM 12 or the auxiliary storage device 14. The processor 11 operates as the RIP 111 by executing the control process of FIG. 2 and FIG. The processor 11 operates as the analysis unit 112 by executing the control process of FIG. 2. The processor 11 operates as the drawing processing unit 113 by executing the control processing of FIG. Alternatively, the processor 11 operates as the drawing processing unit 113 by executing the drawing process shown in FIG. The processor 11 operates as a plurality of drawing processing units 113 by executing a plurality of control processes of FIG. 3 or drawing processes shown in FIG. 3 in parallel. FIG. 5 is a flowchart of hardware processing by the compression core 15 of the image forming apparatus 10. When the processor 11 starts the control process shown in FIG. 3, the variable n and the variable F1 are assigned to the RAM 13 and the like. The variable n indicates the page number of the print target data to be analyzed. The variable F1 is a flag indicating that the drawing monitoring process is being executed. The initial value of the variable F1 is False. Further, when the processor 11 starts the control process shown in FIG. 4, the variable F2 is assigned to the RAM 13 and the like. The variable F2 is a flag indicating that the compression monitoring process is being executed. The initial value of the variable F2 is False.
Unless otherwise specified, the processor 11 and the compression core 15 proceed to Act (n + 1) after processing Act (n) (n is a natural number).

If the processor 11 has print target data that has not been RIP-processed, the control process shown in FIG. 2 is started. The print target data is included in, for example, a print job. The control process shown in FIG. 2 includes an analysis process. The analysis process includes Act1 to Act12 and Act14.

In Act 1 of FIG. 2, the processor 11 of the image forming apparatus 10 sets the value of the variable n to 1.
In Act2, the processor 11 converts the nth page of the print target data into intermediate data.

In Act 3, the processor 11 determines whether or not the drawing monitoring process is being executed. That is, the processor 11 determines, for example, whether or not the value of the variable F1 is True. If the drawing monitoring process is not being executed, the processor 11 determines No in Act 3 and proceeds to Act 4.

In Act4, the processor 11 acquires the number of free cores. That is, the processor 11 acquires the value of the variable q from the RAM 13 and the like.
In Act5, the processor 11 acquires the number of drawing threads. That is, the processor 11 acquires the value of the variable p from the RAM 13 and the like.

In Act6, the processor 11 determines whether or not (the number of free cores q + the set value k)> (the number of data in preparation) is satisfied. The number of data being prepared is the number of data being prepared for compression processing. That is, for example, (number of data being prepared) = (number of drawing threads p). If the processor 11 satisfies (number of free cores q + set value k)> (number of data in preparation), the processor 11 determines Yes in Act 6 and proceeds to Act 7.

In Act 7, the processor 11 increments the value of the variable p by 1 to indicate that the drawing process is started.

In Act 8, the processor 11 starts the drawing process for the intermediate data on the nth page. That is, the processor 11 starts the control process shown in FIG. At this time, the processor 11 passes, for example, the intermediate data of the nth page to the control process. The processor 11 processes the control process shown in FIG. 3 in parallel or in parallel with the control process shown in FIG. 2 by executing the control process shown in FIG. 3 in a thread different from the control process shown in FIG. Preferably, the processor 11 processes in parallel. Further, when the processor 11 is executing another drawing process, the processor 11 executes the control process shown in FIG. 3 in a thread different from the drawing process that is already being executed, so that the processor 11 can execute the control process in parallel with the drawing process that is already being executed. Process in parallel. Preferably, the processor 11 processes in parallel. From the above, the processor 11 may process the drawing process at the maximum (number of compression cores 15 + set value k) in parallel or in parallel with the threads. The processor 11 proceeds to Act9 after the processing of Act8 in FIG.

In Act9, the processor 11 determines whether or not all the pages of the print target data have been analyzed. That is, the processor 11 determines, for example, whether or not the number of pages of print target data is larger than n. If the number of pages of print target data is larger than n, the processor 11 determines Yes in Act9 and proceeds to Act10.

In Act 10, the processor 11 increments the value of the variable n by 1 in order to change the target of the analysis process to the next page. The processor 11 returns to Act1 after processing Act10. On the other hand, if the number of pages of the print target data is not larger than n, the processor 11 determines No in Act9 and ends the analysis process. Thus, the processor 11 repeats Act1 to Act10 until the value of n becomes the number of pages of the print target data. As a result, the processor 11 performs analysis processing on all pages of the print target data.

If the processor 11 does not satisfy (number of free cores + k)> (number of data in preparation), the processor 11 determines No in Act 6 and proceeds to Act 11.
In Act 11, the processor 11 sets the value of the variable F1 to True in order to indicate that the drawing monitoring process is being executed.

In Act 12, the processor 11 adds the intermediate data of the nth page to the drawing waiting queue. The drawing wait queue is a list of intermediate data waiting for drawing processing. The processor 11 starts one new thread after the processing of Act12. Then, the processor 11 proceeds to Act9 in the existing thread. Further, the processor 11 starts the drawing monitoring process shown in Act 13 in a new thread. The processing of Act13 includes the processing of Act131 to Act137.

In Act 131, the processor 11 acquires the number of free cores in the same manner as in Act 4.
In Act 132, the processor 11 acquires the number of drawing threads in the same manner as in Act 5.

In Act133, the processor 11 determines whether or not (the number of free cores q + the set value k)> (the number of data in preparation) is satisfied, similarly to Act6. If the processor 11 does not satisfy (number of free cores q + set value k)> (number of data in preparation), the processor 11 determines No in Act 133 and returns to Act 131. On the other hand, if the processor 11 satisfies (number of free cores q + set value k)> (number of data in preparation), the processor 11 determines Yes in Act 133 and proceeds to Act 134.

In Act 134, the processor 11 increments the value of the variable p by 1 to indicate that the drawing process is to be started.
In Act135, the processor 11 selects the intermediate data first added to the drawing waiting queue from the intermediate data included in the drawing waiting queue. Then, the processor 11 starts the drawing process for the intermediate data in the same manner as the Act 8. Further, the processor 11 deletes the intermediate data from the drawing waiting queue.

In Act 136, the processor 11 determines whether or not there is intermediate data waiting for drawing processing. That is, the processor 11 determines whether or not there is intermediate data in the drawing waiting queue. If there is intermediate data waiting for drawing processing, the processor 11 determines Yes in Act 23 and returns to Act 131. On the other hand, if there is no intermediate data waiting for the drawing process, the processor 11 determines No in Act 136 and proceeds to Act 137.

In Act137, the processor 11 sets the value of the variable F1 to False in order to indicate that the drawing monitoring process is not being executed. The processor 11 ends the drawing monitoring process after the process of Act137. Then, the processor 11 terminates the thread that was performing the drawing monitoring process.

If the drawing monitoring process is being executed at the time of the process of Act 3, the processor 11 determines Yes in Act 3 and proceeds to Act 14.
In Act 14, the processor 11 adds the intermediate data of the nth page to the drawing waiting queue. The processor 11 proceeds to Act9 after processing Act14.

Next, the control process shown in FIG. 3 will be described. The control process shown in FIG. 3 includes a drawing process. The drawing process includes Act31 to Act40 and Act42.
In Act 31 of FIG. 3, the processor 11 generates print data from the target intermediate data. The target intermediate data is, for example, passed from an analysis process or a drawing monitoring process.

In Act 32, the processor 11 determines whether or not the compression monitoring process is being executed. That is, the processor 11 determines, for example, whether or not the value of the variable F2 is True. If the compression monitoring process is not being executed, the processor 11 determines No in Act 32 and proceeds to Act 33.

In Act 33, the processor 11 acquires the compression core information from the RAM 13 and the like.
In Act 34, the processor 11 refers to the compression core information acquired in Act 33 and determines whether or not there is an idle compression core 15. Alternatively, the processor 11 may determine whether the value of the variable q is greater than 0. If there is an idle compression core 15, the processor 11 determines Yes in Act 34 and proceeds to Act 35.

At Act 35, the processor 11 decrements the value of the variable q by 1 to indicate that the number of idle compression cores 15 is reduced.
In Act 36, the processor 11 transmits a compression request requesting compression processing to the idle compression core 15. The compression request includes print data converted by Act31.

On the other hand, in Act 51 of FIG. 4, the compression core 15 waits for a compression request to be transmitted. When the compression core 15 receives the compression request, the compression core 15 determines Yes in the Act 51 and proceeds to the Act 52.

In Act 52, the compression core 15 sends a first core notification to the processor 11 to indicate that the compression core 15 is in a busy state. The first core notification includes the core ID of the compressed core 15 that is the source of the first core notification. Upon receiving the first core notification, the processor 11 updates the compressed core information and changes the parameter associated with the core ID included in the first core notification to indicate the busy state.

In Act53, the compression core 15 performs data compression on the print data included in the compression request received in Act51. The data generated by the data compression is hereinafter referred to as "compressed data".

In Act 54, the compression core 15 transmits the compressed data generated by Act 53 to the auxiliary storage device 14. The auxiliary storage device 14 that has received the compressed data stores the compressed data.

In Act 55, the compression core 15 sends a second core notification to the processor 11 to indicate that the compression core 15 has become idle. The second core notification includes the core ID of the compressed core 15 that is the source of the second core notification. Upon receiving the second core notification, the processor 11 updates the compressed core information and changes the parameter associated with the core ID included in the second core notification to indicate the idle state. Also, the processor 11 increments the value of the variable q by 1 to indicate that the number of idle compression cores 15 has increased.

On the other hand, the processor 11 proceeds to Act37 after the processing of Act36 in FIG.
In Act37, the processor 11 decrements the value of the variable p by 1 to indicate that the drawing process has been completed. The processor 11 ends the drawing process after the process of Act 37. Then, the processor 11 terminates the thread that was performing the drawing process.

If there is no idle compression core 15, the processor 11 determines No in Act 34 and proceeds to Act 38.
In Act 38, the processor 11 sets the value of the variable F2 to True to indicate that the compression monitoring process is being executed.

In Act 39, the processor 11 increments the value of the variable r by 1 to indicate that the number of waits for compression has increased.
In the Act 40, the processor 11 adds the print data converted in the Act 31 to the compression waiting queue. The processor 11 starts one new thread after the processing of Act40. Then, the processor 11 proceeds to Act37 in the existing thread. Further, the processor 11 starts the drawing monitoring process shown in Act 41 in a new thread. The processing of Act 41 includes the processing of Act 411 to Act 416.

In Act 411, the processor 11 acquires the compression core information in the same manner as in Act 33.
In Act412, the processor 11 refers to the compression core information acquired in Act411 and determines whether or not there is an idle compression core 15. Alternatively, the processor 11 may determine whether the value of the variable q is greater than 0. If there is no idle compression core 15, the processor 11 determines No in Act412 and returns to Act411. On the other hand, if there is an idle compression core 15, the processor 11 determines Yes in Act412 and proceeds to Act413.

In Act 413, the processor 11 decrements the value of the variable q by 1 to indicate that the number of idle compression cores 15 is reduced. Further, the processor 11 decrements the value of the variable r by 1 to indicate that the number of waiting for compression is reduced.

In Act 414, the processor 11 sends a compression request to the idle compression core 15 to perform compression processing. The compression request includes print data that is first added to the compression wait queue among the print data included in the compression wait queue. Further, the processor 11 deletes the print data from the compression waiting queue.

In Act415, the processor 11 determines whether or not there is print data waiting for compression processing. That is, the processor 11 determines whether or not there is print data in the compression waiting queue. If there is print data waiting for compression processing, the processor 11 determines Yes in Act415 and returns to Act411. On the other hand, if there is no print data waiting for compression processing, the processor 11 determines No in Act415 and proceeds to Act416.

In Act 416, the processor 11 sets the value of the variable F2 to False in order to indicate that the compression monitoring process is not being executed. The processor 11 ends the compression monitoring process after the process of Act 416. Then, the processor 11 terminates the thread that was performing the compression monitoring process.

If the compression monitoring process is being executed at the time of the Act 32 process, the processor 11 determines Yes in the Act 32 and proceeds to the Act 42.
In Act 42, the processor 11 adds the print data converted by Act 31 to the compression waiting queue. The processor 11 proceeds to Act 37 after processing Act 42.

When the processor 11 finishes converting the print data included in the print job into the compressed data, the processor 11 prints the compressed data based on the print job, for example. That is, the processor 11 controls the image forming unit 16 to print the compressed data stored in the auxiliary storage device 14.

The image forming apparatus 10 of the embodiment can efficiently use the processor 11. The reason is described below.
The conventional image forming apparatus performs RIP processing and compression processing as shown in FIG. 5, for example. FIG. 5 is a diagram showing an example of processing timing of conventional RIP processing and compression processing. In the example of FIG. 5, the processor performs the analysis process in the thread 1 and the drawing process in the thread 2. Also, in the example of FIG. 5, the image forming apparatus includes one compression core.
The analysis unit first performs an analysis process targeting the first page. Then, when the analysis process for the first page is completed, the analysis unit requests the drawing processing unit to start the drawing process for the first page. Then, the analysis unit continues to start the analysis process for the second page.
On the other hand, the drawing processing unit starts the drawing process for the first page in response to the request for starting the drawing process for the first page. Then, when the drawing process for the first page is completed, the drawing processing unit requests the compression core to compress the image data.
In general, the drawing process takes longer than the data analysis. Therefore, while the drawing processing unit is performing the drawing processing for the first page in the thread 2, the analysis unit completes the analysis processing for the second page. Further, the analysis unit requests the drawing processing unit to start the drawing processing for the second page. However, at this time, the drawing processing unit is in the middle of drawing processing for the first page. Therefore, the drawing process for the second page cannot be started immediately. Similarly, even after the third page, the drawing process cannot be started immediately, and a process wait occurs. Then, as shown in FIG. 5, the time for waiting for the drawing process may become longer as the page becomes later. Further, in the example of FIG. 5, the drawing process takes longer than the compression process. Therefore, after the compression process is performed, the compression core is in a state of not being used until the drawing process unit finishes the drawing process of the next page.

Next, FIG. 6 shows an example in which a plurality of drawing processes are processed in parallel by multithreading. FIG. 6 is a diagram showing an example of processing timing of RIP processing and compression processing. In the example of FIG. 6, unlike the example of FIG. 5, the image forming apparatus can perform the drawing process in two threads, thread 2 and thread 3, respectively. In the example of FIG. 6, the analysis unit requests the vacant one of the threads 2 and 3 to start the drawing process every time the analysis process for one page is completed. As a result, by performing the drawing process in each of the plurality of threads, the waiting for the drawing process is less likely to occur as compared with the example of FIG. In the example of FIG. 6, the drawing process waiting does not occur. Further, the compression core is not in an unused state as in the example shown in FIG. 5 after the compression process is performed. However, in the example of FIG. 6, when the drawing processing unit completes the drawing process for the second page, the compression core has not yet completed the compression process for the first page. Therefore, even if the drawing processing unit completes the drawing process for the second page, the compression core cannot immediately perform the compression process for the second page. Similarly, even on the third and subsequent pages, the compression core cannot perform the compression process immediately after the drawing process is completed. Then, as shown in FIG. 6, the time for waiting for the compression process may become longer as the page becomes later. As described above, even if the processor advances the RIP processing quickly, the overall processing speed does not improve if the compression processing wait occurs due to the fact that the compression core is not available. Not only that, the processor usage will increase unnecessarily.

FIG. 7 shows an example of the processing timing of the RIP processing and the compression processing in the image forming apparatus 10 of the embodiment. In the example of FIG. 7, the image forming apparatus 10 includes one compression core 15 as in the examples of FIGS. 5 and 6. In the example of FIG. 7, the set value k = 1.
In the example of FIG. 7, when the analysis process of the third page is completed, the compression process of the first page is being executed by the compression core 15, and the drawing process for the second page is being executed by the drawing processing unit. be. Then, the compression core 15 starts the compression process of the second page after completing the compression process of the first page. Therefore, it is considered that even if the drawing process for the third page is performed at this point, it does not contribute to the improvement of the overall processing speed, but only increases the processor usage rate. Therefore, the image forming apparatus 10 of the embodiment does not start the drawing process for the third page until the compression process of the first page is completed. By doing so, in the example of FIG. 7, the processor usage rate is lower than that of the example of FIG. However, the overall processing speed in the example of FIG. 7 is equivalent to that of FIG. Therefore, it can be said that the image forming apparatus 10 of the embodiment efficiently uses the processor 11.

Further, another example of the image forming apparatus 10 of the embodiment is shown in FIG. FIG. 8 is a diagram showing an example of the processing timing of the RIP processing and the compression processing of the embodiment. In the example of FIG. 8, unlike the examples of FIGS. 5 to 7, the image forming apparatus 10 includes two compression cores 15. Also in the example of FIG. 8, when the analysis process of the third page is completed as in the example of FIG. 7, the compression process of the first page is being executed by the first compression core 15, and the second page is targeted. The drawing process is being executed by the drawing process unit. However, in the example of FIG. 8, since there are two compression cores 15, the second compression core 15 is used without waiting for the first compression core 15 to complete the compression process of the first page. It is possible to start the page compression process. Therefore, in the example of FIG. 8, unlike the example of FIG. 7, it is possible to contribute to the improvement of the overall processing speed by starting the drawing process for the third page. Therefore, in the example of FIG. 8, unlike the example of FIG. 7, the drawing processing unit immediately starts the drawing process for the third page. Further, in the example of FIG. 8, since there are a plurality of compression cores 15, there is no waiting for compression processing. Therefore, it can be said that the image forming apparatus 10 of the embodiment efficiently uses the processor 11.

As described above, in the image forming apparatus 10 of the embodiment, the start timing of the drawing process changes according to the number of compression cores 15. That is, it can be said that the image forming apparatus 10 of the embodiment can efficiently use the processor 11 according to the number of compression cores 15.

Further, the image forming apparatus 10 of the embodiment does not start a new drawing process when the number of data being prepared is k or more larger than the number of the compressed cores 15 in the idle state. It is considered that when the number of data being prepared is k or more larger than the number of compressed cores 15 in the idle state, it does not contribute to the improvement of the overall processing speed as compared with the case where the drawing process is performed when the number of data being prepared is less than this. Therefore, by not starting the drawing process in such a state, the image forming apparatus 10 of the embodiment can prevent the usage rate of the processor 11 from increasing unnecessarily.

The above embodiment can be modified as follows.
In the above embodiment, (number of data being prepared) = (number of drawing threads p). However, (number of data in preparation) = (number of drawing threads p + number of waiting for compression r) may be used. Since the number of data being prepared includes the number of waiting for compression, it is possible to prevent the number of waiting for compression from increasing when the compression process takes a long time. Further, since the number of drawing threads is reduced according to the number of waiting for compression, it may be possible to prevent an increase in the usage rate of the processor 11 that does not contribute to the improvement of the overall processing speed.

The compression core 15 may notify the processor 11 that the compressed data has been generated after the processing of the Act 53. Then, the compression core 15 may transmit the compressed data to the auxiliary storage device under the control of the processor 11.

In the above embodiment, the processor 11 executes a program that performs analysis processing and drawing monitoring processing in separate threads. However, instead of this program, the processor 11 may execute a program that processes the analysis process and the drawing monitoring process in the same thread.
In the above embodiment, the processor 11 executes a program that performs drawing processing and compression monitoring processing in separate threads. However, instead of this program, the processor 11 may execute a program that processes the drawing process and the compression monitoring process in the same thread.

The processor 11 may perform the processing performed by the multi-thread in the above embodiment by the multi-process.

This embodiment can be applied even when the data to be printed is not PDL. That is, the present embodiment can be applied to a process of converting non-PDL print target data into print data and a compression process of compressing the print data.

The image forming apparatus 10 may perform drawing processing on the data of one recording medium including the plurality of pages in order to print the plurality of pages on one recording medium. In this case, the data for one recording medium is an example of one printing unit.
The image forming apparatus 10 may perform drawing processing on the data of one recording medium obtained by dividing one page into a plurality of sheets for printing by dividing one page into a plurality of recording media. good. In this case, the data for one recording medium is an example of one printing unit.

The image forming apparatus of this embodiment does not have to include the compression core 15. Then, instead of the compression core 15, the processor 11 may perform the same processing as the compression processing in parallel or in parallel, such as by executing the same processing as the analysis processing and the drawing processing in a thread different from the analysis processing and the drawing processing. In this case, the processor 11 operates as a compression unit by performing the same processing as the compression processing.
In the image forming apparatus of this embodiment, the processor may have a built-in compression core.
The image forming apparatus of this embodiment may process a plurality of threads in parallel by hardware multithreading.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.
The inventions described in the original claims of the present application are described below.
[1] Data compression is performed on a plurality of drawing processing units that perform drawing processing for converting print target data divided into a plurality of print units into print data, and the print data converted by the drawing process. The drawing processing unit includes a compression unit, and the number obtained by adding a predetermined number to the number of the compression units in an idle state is larger than the number of print units of the print target data being converted into the print data. If so, the image processing apparatus that starts the next drawing process.
[2] The image processing apparatus according to Appendix [1], which comprises a plurality of the compression units and performs the plurality of data compressions in parallel by the plurality of compression units.
[3] The drawing processing unit performs compression processing with the number of printing units of the printing target data being converted into the printing data by adding the predetermined number to the number of the compressed units in the idle state. The image processing apparatus according to Supplementary Note [1] or [2], wherein the drawing process is newly started when the number is larger than the sum of the number of print units of the print data.
[4] A plurality of drawing processes for converting print target data into print data are performed in parallel, the print data converted by the drawing process is compressed, and the data is idle from the number of data being prepared for compression processing. An image processing method for starting a new drawing process when the number obtained by subtracting the number of compressed sections is smaller than a predetermined number.
[5] A computer equipped with a device provided with a compression unit that compresses data for printing is subjected to drawing processing for converting print target data divided into a plurality of print units into the print data. When the drawing processing unit functions as a processing unit and the number obtained by adding a predetermined number to the number of the compressed units in the idle state is larger than the number of printing units of the printing target data being converted into the printing data. , A program that starts the next drawing process.

10 ... image forming device, 11 ... processor, 12 ... ROM, 13 ... RAM, 14 ... auxiliary storage device, 15 ... compression core, 16 ... image forming unit, 17 ... bus, 111 ... RIP, 112 ... Analysis unit, 113 ... Drawing processing unit

Claims (8)

An analysis unit that performs analysis processing to convert print target data into intermediate data divided into multiple print units, and an analysis unit.
A plurality of drawing processing units that perform drawing processing in parallel to convert the intermediate data divided into the plurality of printing units into printing data, respectively .
A compression unit that compresses the print data converted by the drawing process, and a compression unit.
Equipped with
The analysis unit
Each time the first intermediate data is converted from the print target data, the number obtained by adding an arbitrary set value larger than zero to the number of the idle compressed portions is the second number being converted into the print data. Compare whether it is larger than the number of intermediate data in
When the added number is larger than the number of the second intermediate data, the drawing processing unit that has not executed the drawing process is instructed to start the drawing process of the first intermediate data.
When the added number is not larger than the number of the second intermediate data, the first intermediate data is added to the drawing waiting queue, and the added number becomes larger than the number of the second intermediate data. An image processing device that commands a drawing processing unit that has not executed the drawing process to start drawing processing of the first intermediate data added to the drawing waiting queue . The drawing processing unit is
Each time the intermediate data is converted into print data, it is determined whether or not there is the compressed portion in an idle state.
When there is the compression unit in the idle state, the compression unit is instructed to perform the compression processing of the print data converted from the intermediate data.
If there is no compression unit in the idle state, the print data converted from the intermediate data is added to the compression waiting queue, and when the compression unit becomes idle, the print data added to the compression waiting queue is added. The image processing apparatus according to claim 1, wherein the compression unit is instructed to perform the compression processing of the above. The analysis unit
Each time the first intermediate data is converted from the print target data, the number obtained by adding the set value to the number of idle compression units is the number of the second intermediate data being converted into the print data. Compare whether or not it is larger than the sum of the number of print data added to the compression wait queue.
When the number obtained by adding the set value to the number of the compressed portions in the idle state is larger than the number obtained by adding the number of the print data added to the compression waiting queue to the number of the second intermediate data. , Instructs the drawing processing unit that has not executed the drawing process to start the drawing process of the first intermediate data.
The number obtained by adding the set value to the number of the compressed portions in the idle state is not larger than the number obtained by adding the number of the print data added to the compression waiting queue to the number of the second intermediate data. In this case, the first intermediate data is added to the drawing waiting queue, and the number obtained by adding the set value to the number of the compressed units in the idle state is added to the number of the second intermediate data to the compression waiting queue. When the number becomes larger than the sum of the number of print data, the drawing process of the first intermediate data added to the drawing wait queue is started for the drawing process unit that has not executed the drawing process. The image processing apparatus according to claim 2, which is instructed. With a plurality of the compression parts,
The image processing apparatus according to any one of claims 1 to 3, wherein the plurality of compression units simultaneously perform data compression of the plurality of print data . An analysis unit that performs analysis processing that converts print target data into intermediate data divided into multiple print units and a drawing process that converts the intermediate data divided into the plurality of print units into print data are performed in parallel. An image processing method of an image processing apparatus including a plurality of drawing processing units to be performed and a compression unit for compressing data for the print data converted by the drawing processing.
The analysis unit
Each time the first intermediate data is converted from the print target data, the number obtained by adding an arbitrary set value larger than zero to the number of the idle compressed portions is the second number being converted into the print data. Compare whether it is larger than the number of intermediate data in
When the added number is larger than the number of the second intermediate data, the drawing processing unit that has not executed the drawing process is instructed to start the drawing process of the first intermediate data.
When the added number is not larger than the number of the second intermediate data, the first intermediate data is added to the drawing waiting queue, and the added number becomes larger than the number of the second intermediate data. An image processing method for instructing a drawing processing unit that has not executed the drawing process to start drawing processing of the first intermediate data added to the drawing waiting queue. The drawing processing unit
Each time the intermediate data is converted into print data, it is determined whether or not there is the compressed portion in an idle state.
When there is the compression unit in the idle state, the compression unit is instructed to perform the compression processing of the print data converted from the intermediate data.
If there is no compression unit in the idle state, the print data converted from the intermediate data is added to the compression waiting queue, and when the compression unit becomes idle, the print data added to the compression waiting queue is added. The image processing method according to claim 5, wherein the compression unit is instructed to perform the compression processing of the above. An analysis unit that performs analysis processing that converts print target data into intermediate data divided into multiple print units and a drawing process that converts the intermediate data divided into the plurality of print units into print data are performed in parallel. A computer of an image processing apparatus including a plurality of drawing processing units for performing data compression and a compression unit for compressing data for printing data converted by the drawing processing .
The analysis unit
Each time the first intermediate data is converted from the print target data, the number obtained by adding an arbitrary set value larger than zero to the number of the idle compressed portions is the second number being converted into the print data. A means of comparing whether or not it is larger than the number of intermediate data in
When the added number is larger than the number of the second intermediate data, the means for instructing the drawing processing unit that has not executed the drawing process to start the drawing process of the first intermediate data, and
When the added number is not larger than the number of the second intermediate data, the first intermediate data is added to the drawing waiting queue, and the added number becomes larger than the number of the second intermediate data. A means for instructing a drawing processing unit that has not executed the drawing process to start drawing processing of the first intermediate data added to the drawing waiting queue.
A program to function as . The computer of the image processing device, and further
The drawing processing unit
A means for determining whether or not there is an idle compressed portion each time the intermediate data is converted into print data.
A means for instructing the compression unit to perform compression processing of the printing data converted from the intermediate data when there is the compression unit in the idle state.
If there is no compression unit in the idle state, the print data converted from the intermediate data is added to the compression waiting queue, and when the compression unit becomes idle, the print data added to the compression waiting queue is added. A means for instructing the compression unit to perform the compression process of
7. The program according to claim 7.

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